This invention relates to a tone arm drive device, and more particularly to a tone arm automatic drive device in an audio record player.
The tone arm of an audio record player is moved upwardly upon leaving the arm rest at the time when record playback is to start, and after being swung horizontally to the playback start point above the record disk, the tone arm is then lowered onto the surface of the disk. When record playback is complete, the tone arm is elevated from the surface of the record disk, horizontally swung back to the arm rest, and finally lowered onto the arm rest. A variety of audio record players having an automatic playback device automatically carrying out a series of tone arm operations as described above are known in the art. With this type of record player, upon the start of automatic playback, a tone arm elevation mechanism is first operated to elevate the tone arm above the arm rest, and then it is horizontally swung to the playback start point on the record disk. That is, a so-called "lead-in" operation is carried out.
During the lead-in operation, the automatic playback start can be temporarily suspended by performing an elevation instruction operation, if necessary. In this case, the lead-in operation is continued, and when the tone arm reaches the playback start point on the record disk, a descent position signal is generated to stop the operation of the automatic playback device. The tone arm is maintained stationary above a position to which it is to be lowered, because an "elevation" instruction is maintained in the internal electrical circuit by the elevation operation performed previously. Accordingly, as described later, the tone arm drive mechanism is maintained mechanically engaged with the tone arm. Therefore, it is substantially impossible for the operator to move the tone arm to other positions above the record disk. This is a substantial inconvenience and disadvantage of such systems.
Conversely, when the automatic playback start instruction operation is performed after the elevation instruction, in order to elevate the tone arm initially, the tone arm is elevated in response to the elevation instruction. Thereafter, the tone arm is horizontally swung in response to the automatic playback instruction. When the descent position signal is generated by the descent position detector, the tone arm is stopped at the position without lowering itself, because the circuit is maintained in an "elevation" instruction state by the elevation instruction. Accordingly, similarly as in the above-described case, it is difficult for the operator to move the tone arm.